Parameter info popup after completion insertion.

Do not add '(' if it's already exist in completion (+Tests).

idea/src/org/jetbrains/jet/plugin/completion/handlers/JetFunctionInsertHandler.java

@@ -1,10 +1,13 @@
 package org.jetbrains.jet.plugin.completion.handlers;
 
+import com.intellij.codeInsight.AutoPopupController;
 import com.intellij.codeInsight.completion.InsertHandler;
 import com.intellij.codeInsight.completion.InsertionContext;
 import com.intellij.codeInsight.lookup.LookupElement;
+import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.psi.PsiDocumentManager;
+import com.intellij.psi.PsiElement;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.DescriptorsUtils;
 import org.jetbrains.jet.lang.descriptors.NamedFunctionDescriptor;
@@ -34,14 +37,26 @@ public class JetFunctionInsertHandler implements InsertHandler<LookupElement> {
         }
 
         int startOffset = context.getStartOffset();
+        PsiElement element = context.getFile().findElementAt(startOffset);
+        if (element == null) return;
         int lookupStringLength = item.getLookupString().length();
         int endOffset = startOffset + lookupStringLength;
+        Document document = context.getDocument();
 
-        context.getDocument().insertString(endOffset, "()");
+        boolean bothParentheses = false;
+        String documentText = document.getText();
+        if (documentText.charAt(endOffset) != '(') {
+            //do not insert () if it already exists.
+            document.insertString(endOffset, "()");
+            bothParentheses = true;
+        } else if (documentText.charAt(endOffset + 1) == ')') {
+            bothParentheses = true;
+        }
 
         Editor editor = context.getEditor();
-        if (caretPosition == CaretPosition.IN_BRACKETS) {
+        if (caretPosition == CaretPosition.IN_BRACKETS || !bothParentheses) {
             editor.getCaretModel().moveToOffset(editor.getCaretModel().getOffset() + 1);
+            AutoPopupController.getInstance(context.getProject()).autoPopupParameterInfo(editor, element);
         } else {
             editor.getCaretModel().moveToOffset(editor.getCaretModel().getOffset() + 2);
         }

idea/testData/completion/handlers/ExistingNoParamsFunction.kt

@@ -0,0 +1,10 @@
+package testing.handlers
+
+fun test() {
+}
+
+fun other() {
+    te<caret>()
+}
+
+// INSERT: test

idea/testData/completion/handlers/ExistingNoParamsFunction.kt.after

@@ -0,0 +1,10 @@
+package testing.handlers
+
+fun test() {
+}
+
+fun other() {
+    test()<caret>
+}
+
+// INSERT: test

idea/testData/completion/handlers/ExistingSingleBrackets.kt

@@ -0,0 +1,13 @@
+package Test.MyTest
+
+class A {
+    class object {
+        public fun testOther(a: Int) {
+
+        }
+    }
+}
+
+fun testMy() {
+    A.testOthe<caret>()
+}

idea/testData/completion/handlers/ExistingSingleBrackets.kt.after

@@ -0,0 +1,13 @@
+package Test.MyTest
+
+class A {
+    class object {
+        public fun testOther(a: Int) {
+
+        }
+    }
+}
+
+fun testMy() {
+    A.testOther(<caret>)
+}

idea/tests/org/jetbrains/jet/completion/handlers/CompletionHandlerTest.java

@@ -11,6 +11,10 @@ import java.io.File;
  */
 public class CompletionHandlerTest extends LightCompletionTestCase {
 
+    public void testExistingNoParamsFunction() {
+        doTest();
+    }
+
     public void testNoParamsFunction() {
         doTest();
     }
@@ -33,6 +37,10 @@ public class CompletionHandlerTest extends LightCompletionTestCase {
         checkResultByFile("SingleBrackets.kt.after");
     }
 
+    public void testExistingSingleBrackets() {
+        doTest();
+    }
+
     public void doTest() {
         String fileName = getTestName(false);
         try {